A retaining clip or ring is a device which fits in a groove on a shaft or bore to locate one or more other components relative to the shaft or bore. An external retaining ring is typically disposed in a groove on an outer surface of a shaft, and an internal retaining ring is typically disposed in a groove on an inner surface of a bore or housing.
Known retaining rings provide either complete or incomplete coverage of the 360 degree groove surface. Examples of known incomplete retaining rings include “snap rings” (also known as “circlips”), “e-rings” and “crescent rings”. Examples of known complete retaining rings include “spiral rings” such as the Spirolox® retaining ring produced by Smalley Ring Steel Company. Spiral retaining rings are typically formed by coiling a flat wire to form a 2-turn or 3-turn spiral. Retaining rings are in wide usage across a variety of industries including aerospace, automotive, mining and drilling.
Where a complete external retaining ring is required, the spiral ring can be problematic to install and remove in certain applications. For example, in the case where the shaft has significant length, then it may become difficult to maintain the spiral ring in an expanded state, due to space constraints for tooling for example, as it is moved along the length of the shaft up to the location of the groove in which it is to be seated. Furthermore, the shaft may have components located upon it that are of softer material than the spiral ring, such as O-ring seals, for example. If a clearance cannot be maintained between the expanded spiral ring and the seal then sliding the spiral ring over the seal may cause damage to the seal. Similar problems to those described above may also be observed with internal spiral rings.
There is therefore a need for an improved retaining ring, which overcomes the installation problems that may be found with spiral rings.